RADIATIVE AND NONRADIATIVE DECAYS OF LA 4D IONIZED AND EXCITED-STATES

The probabilities of creation and decay of La4+ 4d9 and La3+ 4d94f1 configurations are calculated using a multiconfiguration, Dirac-Fock code. Both x-ray- and Auger-emission spectra are simulated and compared with experimental electron-induced spectra. This comparison leads to an original interpretation of the spectra. We show that the decay rate of the excited 4d94f1 state to discrete states is larger than that of the 4d9 ionized state. In particular, for the La3+ 4d94f1 1P1 level that had been attributed to a "giant resonance," we find a decay rate to discrete states a hundred times greater than that of 4d9. A comparison of the 4d94f1 and 4d9 confiugration energies as well as values of the cross section of the ground state to each of these two high configurations is made for the three cases of La, La2+, and La3+. © 1994 The American Physical Society.